Core for heat exchange unit



Sept. 29, 1959 A. G. GETZ 2,906,508

CORE FOR HEAT EXCHANGE UNIT Filed Feb. 8, 1956 s Sheets-Sheet 1 INVENTORY CZfrg gi2aadGGef;'/

Sept. 29, 1959 A. G. GETZ CORE FOR HEAT EXCHANGE UNIT 3 Sheets-Sheet 2 Filed Feb. 8, 1956 IN VEN TOR; 9

Sept. 29, 1959 A. G. GETZ CORE FOR HEAT EXCHANGE UNIT Filed Feb. a, 1956 I 3 Sheets-Sheet 3 I? x 7 Z 5 Qmsiad 2,906,508 CORE FOR HEAT EXCHANGE UNIT ArnsteadG. Getz, Lakewood, Ohio, assignor to The 'Bishop & Babcock Manufacturing Company, Cleveland, Ohio, a corporation of Ohio Application February 8, 1956, Serial No. 564,244

4 Claims. (Cl. 257-430) This invention relates to cores for heat exchange units such as automobile radiators and heaters, and has to do with cores of the cellular type fabricated from sheet metal strips.

Cores of the character stated are extensively used. In general, in such cores with which I am familiar the cooling air has, in large portion, free straight line flow through the core from front to back thereof, without being brought into direct heat exchange contact with the metal of the core. The heat transfer capacity of such cores is comparatively low and the amount of metal required to attain a given total heat exchange is rather large, which is reflected in the cost of production.

My invention is directed to a heat exchange cellular core of comparatively high heat exchange capacity in which substantially all of the cooling air is brought into heat exchange contact with the metal of the core. That materially increases the total heat transfer capacity of the core with a corresponding reduction in the amount of metal necessary to attain a given total heat exchange capacity and a material saving in the cost of production. A further important feature of the core of my invention is the provision of means for quickly and accurately positioning the elements of the core in the assembly thereof, such means also strengthening the assembled core and increasing its resistance to vibration and road shock. Speed and ease of assembly, and saving of metal, contribute to reduced cost of production, an important consideration in this field, which is highly competitive. Further objects and advantages of my invention will appear from the detail description. I

In the drawings:

Figure 1 is a front view of a heat exchange unit comprising a cellular core embodying my invention;

Figure 2 is a front view, on an enlarged scale, of three sections of the core of Figure 1;

Figure 3 is a sectional view, on an enlarged scale, taken substantially on line 33 of Figure 2, with portions of the spacer brokenaway, successively from top to bottom, an upper portion of the arm of the spacer adjacentthe water wall being shown in vertical section and theribs .of a portion ofthe other arm of the spacer being indicated in dot and dash lines;

Figurev 4is a sectional view taken substantially on line 4-4 of Figure 3; and

Figure 5 is a sectional view, on an enlarged scale, taken substantially on line 5-5 of Figure 3.

The instant invention is inv the nature of an improvement of the heat exchange unit core of my Patent No. 2.594,008,"issued April 22, 1952. In assembling the core of that patent the separators are positioned relative to thev water walls by means of small positioning elements or bosses pressed from the. crests of the ribs of the separator and engaging the upper and lower sides of ribs pressed from the water walls inwardly of the respective sections of the core. The separator ribs seat at their crests on the water wall ribs and ,are restrained against.

relative vertical movement by the positioning elements.

United States PatentO "ice That core has proved to be highly efficient in respect to saving of metal andspeed of assembly as well as high heat exchange capacity. The forming of the positioning elements or protuberances on the crests of the ribs of the separator requires a separate operation, which adds to the cost of production. I have discovered that it is possible to eliminate that operation, with a correspond,- ing savingincost of production, by providing the water walls with positioning elements or protuberances cooperating with the separator ribs for positioning the latter and restraining them against movement relative to the water walls bothvertically and horizontally, which facilitates assembly-and further reduces cost of production. My present invention is directed particularly to such improvement over the core of my above identified patent.

In Figure l of the; drawings 1 have shown a cellular core 10 embodyingmy invention-and which may be used either in an automobilegheater or in an automobile radiator. The core 10 is provided with flanged top and bottom tanks 11 and 12, respectively, suitably secured thereto, conveniently by soldering. The tanks 11 and 12; open into thevertioal water passages of the core and are respectively, provided with inlet and outlet nipples 13 and 14. The core lllis formed of a suitable number of units or, sections 15suitably assembled and secured together defining between them vertical water passages 16 extending from the top to the bottom of the core, as shown more clearly imFigure 4.

Each of thesections 15- comprises a water wall member 19 and a separator 25} therein. The water wall member 19 is formed from a strip of brass of thin gauge which is flattened transversely at its midlength, at 21, and folded over on itself, the two ends of -the strip being secured together by a lock seam 22. The member 19 thus produced is of elongated rectangular or oblong shape as viewed from in front, as shown more clearly in Figure 2.

The 'front and rear portions of the arms or water walls 23 of the respective members 19 are corrugated at 24 and are slightly offset inwardly relative to the water passages 16, as will appear more fully later. Each of the water walls 23 is provided with spaced parallel transverse ribs 25 pressed inwardly thereof relative to the water passage 16 and projecting but a slight distance, approximately fl inwardly of that passage, the ribs 25 being of slight width, in practice approximately 41, The ribs 25 define therebetween flat areas or lands 26 of substantial width, shown more clearly in Figure 3. The ribs 25 and lands 26 are centered relative to the corrugations 24 and extend therefrom to the midportion of water wall 19, to frusto-pyramidal projections 27 pressed from water wall 19 at the midwidth thereof and extending inward to the water passage 16.

Each land 26 of each of the water walls 23. is provided with a plurality of cylindricalbosses or protuberances 30-.pressedtherefrom inwardly of core section 15, The protuberances 30 are staggered and equally spaced lengthwise of land 19 at opposite sides of the frusto-pyramidal projections 27, there being six protuberances, three at each side of projection, 27 in; each pairof lands 26 ;ex-. tending transversely of the water wall 23,. in the embodiment illustrated. The separator 20 is formed from a strip of copper of light gauge, of the same widthas the brass strip from which the water wall member 19 is formed, and has its front and back edgeportions provided with narrow corrugations 31 straight transversely of the strip and having flattened crests. The separator strip is fur: ther corrugated to provide, at each face thereof, transversely extending continuous ribs 32 of substantial1y..-V-. shape incross section, the crests 36 of which are flattened and extend between. and connect the crests offlaligned corrugations 31 at the edges of the strip. Each of the ribs 32 is provided with seven undulations 33 of arcuate curvature merging smoothly one into the other, the undulations of each rib overlapping the undulations of the two next adjacent ribs for the full height thereof, i.e., the extent of the ribs toward the adjacent water wall 23, or substantially so. Referring to Figure 3, if a straight edge be laid along the apices of the undulations 33 of one of the ribs 32 shown in section, it will intersect the apical portions of the undulations 33 of the next adjacent rib 32. The apices of the undulations 33 of each rib 32 extend at least to, preferably somewhat beyond, lines tangent to the apices of the undulations 33 of the two next adjacent ribs 32, thereby providing truly undulatory air passages between adjacent ribs 32 and precluding possibility of free straight line flow of air through the core between the ribs 32. The corrugated copper separator strip is flattened transversely at its midlength and is folded over on itself to provide two parallel strips or arms 34 connected at one end by the flattened element 35 and free from each other at their other ends. The strip from which the separator 20 is formed is produced in a single operation, as is the strip, including the protuberances 30, from which the water wall member 19 is formed.

The separator 20 is of elongated oblong shape in front view and is of proper length and width to fit within the water wall member 19, with the ribs 32 at the inner faces of arms 34 seating on each other, the ribs 32 at the outer faces of arms 34 seating upon the transverse lands 26 of water walls 23 with the central undulations 33 of each rib 32 spanning the projection 27 and the apices of the other undulations 33 of each rib 32 engaging about the protuberances 30 and extending a short distance over the narrow water wall ribs 25, as in Figure 3. The protuberances 30 thus cooperate with the undulations 33 of ribs 32 for accurately positioning the arms 34 of the separator 20 relative to each other and to the water'walls 23, with the flat crests 36 of the undulatory ribs 32 seating for substantially their full length upon lands 26 in metal to metal contact therewith. As will be understood from what has been said, the ribs 32 at the inner faces of arms 34 of the separator 20 are reversed, that is, the ribs 32 of one arm 34 are reversed relative to the ribs 32 of the other arm 34, the ribs of one arm seating on the ribs of the opposed arm.

The separator 20 formed as above stated, is inserted into the water wall member 19 from front to back thereof, the arms or water walls 23 of member 19 being sprung apart sufliciently for that purpose. After the separator 20 has been thus inserted into the water wall member 19 in position with its front and back edges approximately flush with the front and back edges of the water wall member 19, the arms of the latter are released and pressed toward each other. When that occurs, the rounded protuberances 30 of lands 26 engage into the undulations 33 of ribs 32 of the arms 34 of separator 20 and accurately position the separator within the water wall member 19 and restrain it against relative movement either lengthwise or transversely of the water wall member. That eliminates necessity of particular care in assembling the separator and the waterwall member and is conducive to speed in assembly, which is desirable. In the fully inserted position of separator 20 the front and the back edges thereof are flush with the front and the back edges of the water wall member 19, the flat crests 36 of ribs 32 extending outwardly of arms 34 of separator 20 seat upon the lands 26 of the water walls 23 and the flat crests 36 of the opposed inwardly extending ribs 32 of separator 20 seat upon each other; as shown in Figure 3. Since the undulatory ribs 32 at the inner faces of arms 34 of separator 20 are reversed, the bends or undulations 33 of the opposed ribs cross each other providing between them openings 37 establishing communication between the undulatory channels at the top and the bottom of each of the ribs, provided by the ribs at the outer faces of arms 34 of separator 20. The undulations 33 of the ribs 32 overlap, as previously stated and is shown more clearly in Figure 3, providing between the ribs 32 tortuous or undulatory air passages each having a plurality of oppositely directed arcuate bends merging smoothly one into the other. The corrugations at the front and back edge margins of arms 34 of separator 20 define a vertical series of diamond shaped openings for inlet and exit of cooling air to and from the undulatory passages between the ribs 32, and the corrugations 24 of the Water walls 23 define, with the corrugations 31 of arms 34 of separator 20, two vertical series of air inlet openings, at the front of the unit and two vertical series of openings of approximately diamond shape at the back of the unit, between arms 34 of separator 20 and water walls 23, these openings communicating with the undulatory passages between the ribs 32 at the outer faces of arms 34 of separator 20. Cooling air flowing through the passages between the arms of separator 20 and the water walls 23 is forced to flow through an undulatory path effective for imparting high turbulence to such air and bringing it into intimate heat exchange contact with the water walls and with ribs 32 of arms 34 of separator 20. Likewise, air flowing between arms 34 of separator 20 is forced to flow through passages undulatory in a vertical direction and also, due to the crossing of the ribs 32 and the resultant openings 37, flows through tortuous paths horizontally or transversely of the unit comprising the water Wall member and the separator. In that manner, air flowing through the unit is brought into intimate heat exchange contact with the metal walls thereof, thereby assuring high heat exchange efliciency of the unit. The ribs 32 at the outer faces of arms 34 of separator 20 have large area of metal to metal contact with the water walls 23, and the ribs 32 at the inner faces of arms 34 of separator 20 also have large area of contact; assuring a high rate of heat transfer from the water flowing through the water passages, to be explained more fully presently, and the air cooled parts of the structure. The ribs 25 pressed from the water walls 23 inwardly of the water passage 16 impart desired rigidity to the water walls and are quite narrow, as above noted, so that but a slight amount of air can flow through those ribs. Such air as flows through the ribs partakes of the turbulence imparted to the air flowing between the undulatory ribs of the separator and also is in direct contact with the transverse ribs 25 of the water walls 23 so as to abstract heat therefrom, which contributes to the high heat transfer capacity of the core.

In constructing the core of Figure 1, a suitable number of sections, each comprising a Water wall member 19 and a separator 20 therein, are assembled in sideto-side relation, with the marginal corrugations 24 of each water wall 23 nesting in the marginal corrugations of the next adjacent water wall and, in cooperation therewith, positioning the sections accurately in proper relation while spacing the adjacent water walls 23 apart providing therebetween the water passages 16; as in Figure 4. The block of assembled sections is then clamped together in a suitable frame, with the tanks 11 and 12 clamped on the top and the bottom of the block and opening to the water passages 16. The assembly is then dipped, first the front and then the back, in a suitable flux or acid solution, after which the assembly is dipped, first the front and then the back, in molten solder, thus soldering together the water walls and the separators so as to produce as a unitary structure, the core 10. In this clip soldering operation, the solder flows by capillarity between the undulatory ribs 32 at the outer faces of arms 34 of separator 20 and the relatively wide lands 26 at the outer faces of the water walls 23, which are thus secured together in metal to metal contact, conducive to high rate of heat flow from the Water walls to the separators. Referring more particularly to Figures 4 and 5, when the sections are assembled in the manner stated, the projections 27 of the adjacent Water walls 19 mesh and preferably close to space therebetween. In that manner, each of the water passages 16 is separated into a front portion or channel and a rearportion or channel, whereby the Water is divided into two downwardly flowing parallel columns, the projections 27 assisting in transfer of heat from the water to the metal of the water wall 19 and thence to the cooling air fiowing through the undulatory air-passages. Further, the trans- 'verse ribs 25 of the water walls 23 assist intransfer of heat from the water to the coolingair, as above explained. The solderflows by capillarity between the undulatory ribs of the spacerand the lands 26 ofthe water walls 23 securing them together in metal to metal contact and also securing the ribs32 to the protuberances 30 oflands 19, which'pro tuberan'ces 30 provide abutments for ribs 32 imparting desirable strength and rigidity to the core for resisting vibration and road shocks while also providing, in the aggregate, substantial increased area of metal to metal contact between the water walls and the spacer thereby contributing materially to the heat exchange capacity of the core.

In the dip soldering operation the front and the back flanges of the tanks 11 and 12 are soldered to the top and the bottom of the core 10, as will be understood. The side flanges of the tanks may be soldered to the top and the bottom of the core in a suitable known manner. The completely assembled and soldered core, including the tanks 10 and 11, after being inspected and tested, is provided with a protective coating, conveniently by dipping in a suitable coating material. In the completed core the undulatory air passages are of considerable length, as are the undulatory ribs defining such passages, so that the air flows through paths of considerable length and is brought into intimate contact with large areas of metal, which is conducive to high efficiency in effecting rapid abstraction of heat from the metal by the cooling air. Additionally, the cooling air is subjected to high turbulence, which further contributes to the heat exchange capacity of the core, which is supplemented by the tortuous flow horizontally, as well as vertically, of the cooling air passing between the arms 34 of separator 20.

The spacer or separator 20 shown by way of example is a two armed or double spacer, as above described. It is to be understood, however, that the spacer or separator may be either single, i.e., of one thickness only of copper; strip, or multiple with two or more arms, and my invention comprehends separators or spacers of either type.

It will be understood that variations in detail may be resorted to without departing from the field and scope of my invention, and I intend to include all such variations, as fall within the scope of the appended claims, in this application in which the preferred form only of my invention has been disclosed.

I claim:

1. In a cellular core for heat exchange units, a plurality of sections respectively comprising two spaced apart substantially parallel sheet metal water walls and a sheet metal separator between said water walls substantially parallel therewith, said Water walls having at the inner sides thereof fiat transverse lands substantially straight lengthwise and of substantially uniform width each provided with a plurality of protuberances spaced apart lengthwise thereof and extending inwardly of said section toward said separator, the water walls of adjacent sections having front and back marginal portions secured together and being spaced apart therebetween providing water passages between the water walls of adjacent sections, said separator having transverse undulatory corrugations providing undulatory ribs with the undulations of each rib extending at least to lines tangent to the apices of the undulations of the two next adjacent ribs and defining therewith undulatory air passages extending from front to back of said section, theribs of said separator spanning the space betweenthe water walls of said section and having continuous crests respectively seating for substantially their full length on said water wall lands in substantially continuous contact therewith and with the undulations of said ribs respectively engaging about said protuberances and in cooperation there- "with restraining said separator against movement relative to said water walls both lengthwise and transversely thereof.

2. In a cellular core for heat exchange units, a plurality of sections respectively comprising two spaced apart substantially parallel sheet metal water walls and a sheet metal separator between said water walls substantially parallel therewith, said water walls having at the inner sides thereof flat transverse lands substantially straight lengthwise and of'substantiallyuniform width eachprovided with a plurality of protuberances spaced apart lengthwise thereof and extending inwardly of said section toward said separator, the water walls of adjacent sections having front and back marginal portions secured together and being spaced apart therebetween providing water passages between the water walls of adjacent sections, said separator having transverse undulatory corrugations providing undulatory ribs with the undulations of each rib extending at least to lines tangent to the apices of the undulations of the two next adjacent ribs and defining therewith undulatory air passages extending from front to back of said section, the ribs of said separator spanning the space between the water walls of said section and having continuous flat crests of material width respectively seating for substantially their full length on said water wall lands in substantially continuous contact therewith and with the undulations of said rib-s respectively engaging about said protuberances and in cooperation therewith restraining said separator against movement relative to said water walls both lengthwise and transversely thereof.

3. In a cellular core for heat exchange units, a plurality of sections respectively comprising two spaced apart substantially parallel sheet metal water walls and a sheet metal separator between said water walls substantially parallel therewith, said Water walls having at the inner sides thereof flat transverse lands substantially straight lengthwise and of substantially uniform width each provided 'with a plurality of substantially cylindrical protuberances spaced apart lengthwise thereof and extending inwardly of said section toward said separator, the water walls of adjacent sections having front and back marginalportions secured together and being spaced apart there-.- between providing water passages between the water walls of adjacent sections, said separator having transverse undulatorycorrugations providing undulatory ribs with the undulations of each rib extending at least to lines tangent to the apices of the undulations of the two next adjacent ribs and defining therewith undulatory air passages extending from front to back of said section, the ribs of said separator spanning the space between the water walls of said section and having continuous fiat crests of material width respectively seating for substantially their full length on said water wall lands in substantially continuous contact therewith and with the undulations of said ribs respectively engaging about said protuberances and in cooperation therewith restraining said separator against movement relative to said water walls both lengthwise and transversely thereof.

4. In a cellular core for heat exchange units, a plurality of sections respectively comprising two spaced apart substantially parallel sheet metal water walls and a sheet metal separator between said water walls substantially parallel therewith, said water walls having at the inner sides thereof flat transverse lands substantially straight lengthwise and of substantially uniform width each provided with a plurality of substantially cylindrical projections spaced apart lengthwise thereof in staggered relation and extending inwardly of said section toward said separator, the water walls of adjacent sections having front and back marginal portions secured together and being spaced apart therebetween providing water passages between the water Walls of adjacent sections, said separator having transverse undulatory corrugations providing undulatory ribs with the undulations of each rib extending at least to lines tangent to the apices of the undulations of the two next adjacent ribs and defining therewith undulatory air passages extending from front to back of said section, the ribs of said separator spanning the space between the water Walls of said section and having continuous fiat crests of material Width respectively seating for substantially their full length on said water wall lands in substantially continuous contact therewith and with the undulations of said ribs respectively engaging about said protuberances alternately and in cooperation therewith restraining said separator against movement relative to said water walls both lengthwise and transversely thereof.

References Cited in the file of this patent UNITED STATES PATENTS 1,434,853 Spery Nov. 7, 1922 1,468,686 Wolfe Sept. 25, 1923 1,826,344 Dalgliesh Oct. 6, 1931 1,905,447 Diamant Apr. 25, 1933 2,169,993 Booth Aug. 22, 1939 2,594,008 Getz Apr. 22, 1952 2,652,233 Przyborowski Sept. 15, 1953 2,843,365 Getz July 15, 1958 FOREIGN PATENTS 304,183 Great Britain Jan. 16, 1930 

